Prompt: Generate Godoc Comments

Goal

Review existing Go documentation and generate missing godoc comments so every package, type, field, function, and method is documented in an idiomatic, stdlib-style way.

• Top-level package docs must use block comments /* ... */ in a dedicated doc.go.
• All other docs must use line comments // ... immediately preceding the declaration.
• Document everything (exported and unexported) — types, interfaces, funcs, methods, consts, vars, and every struct field.
  • Exception: embedded struct fields may omit comments if they’re purely structural.
• Follow Effective Go and Go Code Review Comments conventions.

Note: Tests are out of scope — see "Scope & Exclusions" below.

Tasks